from turtle import *


my_turtle = Turtle()
my_win = my_turtle.getscreen()


def draw_spiral(my_turtle, line_len):
    if line_len > 0:
        my_turtle.forward(line_len)
        my_turtle.right(90)
        draw_spiral(my_turtle, line_len -5)


draw_spiral(my_turtle, 300)
my_win.exitonclick()